COPY(9) | Kernel Developer's Manual | COPY(9)

# NAME

copy, copyin, copyout, copystr, copyinstr, copyoutstr — kernel space to/from user space copy functions

# SYNOPSIS

#include <sys/types.h>
#include <sys/systm.h>

int
copyin(const void *uaddr, void *kaddr, size_t len);

int
copyout(const void *kaddr, void *uaddr, size_t len);

int
copystr(const void *kfaddr, void *kdaddr, size_t len, size_t *done);

int
copyinstr(const void *uaddr, void *kaddr, size_t len, size_t *done);

int
copyoutstr(const void *kaddr, void *uaddr, size_t len, size_t *done);

int
copyin_proc(struct proc *p, const void *uaddr, void *kaddr, size_t len);

int
copyout_proc(struct proc *p, const void *kaddr, void *uaddr, size_t len);

int
ioctl_copyin(int ioctlflags, const void *src, void *dst, size_t len);

int
ioctl_copyout(int ioctlflags, const void *src, void *dst, size_t len);

# DESCRIPTION

The copy functions are designed to copy contiguous data from one address to another. All but copystr() copy data from user-space to kernel-space or vice-versa.

The copy routines provide the following functionality:

copyin()
  Copies len bytes of data from the user-space address uaddr in the current process to the kernel-space address kaddr.
copyout()
  Copies len bytes of data from the kernel-space address kaddr to the user-space address uaddr in the current process.
copystr()
  Copies a NUL-terminated string, at most len bytes long, from kernel-space address kfaddr to kernel-space address kdaddr. If the done argument is non-NULL, the number of bytes actually copied, including the terminating NUL, is returned in *done.
copyinstr()
  Copies a NUL-terminated string, at most len bytes long, from user-space address uaddr in the current process to kernel-space address kaddr. If the done argument is non-NULL, the number of bytes actually copied, including the terminating NUL, is returned in *done.
copyoutstr()
  Copies a NUL-terminated string, at most len bytes long, from kernel-space address kaddr to user-space address uaddr in the current process. If the done argument is non-NULL, the number of bytes actually copied, including the terminating NUL, is returned in *done.
copyin_proc()
  Like copyin(), except it operates on the address space of the process p.
copyout_proc()
  Like copyout(), except it operates on the address space of the process p.
ioctl_copyin()
  Like copyin(), except it operates on kernel adresses when the FKIOCTL flag is passed in ioctlflags from the ioctl call.
ioctl_copyout()
  Like copyout(), except it operates on kernel adresses when the FKIOCTL flag is passed in ioctlflags from the ioctl call.

# RETURN VALUES

The copy functions return 0 on success or EFAULT if a bad address is encountered. In addition, the copystr(), copyinstr(), and copyoutstr() functions return ENAMETOOLONG if the string is longer than len bytes.

# SEE ALSO

fetch(9), store(9)

August 28, 2005 | NetBSD 7.2